Self-aligning hone or reamer drive for fitting piston pins



c. c. cRAvEN' SELF-A NING HONE OR REAMER DRIVE F FITTING PISTON PINS Filed Deo. 25, 1946 sept. 19, 195o 1 N VEN TOR. I/da 6i C/m/e/ By /A TORN Patented Sept. 19, 1950 SELF-ALIGNING HONE R BEAMER DRIVE FOR FITTING FIST-0N PINS Claud C. Craven, Kansas City, Mo.

Application December 23, 1946, Serial No. 71830102 1 Claim. y t l This invention relates more specically to apparatus for reaming cylindrical bores in members wherein it is desired to enlarge or shape saidbores to a predetermined desired condition.

This invention has to do particularly with connecting rods for 4internal combustion engines or the like and has for its primary object the provision of means for iitting the piston pins into the cylindrical bushing forming a part thereof through use of a reamer drive having parts for definitely and precisely aligning the bore of said bushing with the reamer being used and as the same is caused to rotate about its longitudinal axis. y

One of the most difficult problems in this field lies in the peculiar contour or irregular faces inherent in most internal combustion engine connecting rods, in that such irregular contour causes great diiiiculty in aligning the same `on a reaming tool, tothe end that the bushing being reamed will remain truly parallel to the bearing at the opposite end. In other words, a connecting rod has no denite measuring surface, against which a guide may bear to serve as a measuring or aligning medium when such connecting rod is to be held in operative relationship with a rotatable reaming tool, except the bearing at one end thereof.

It is` the primary object of this invention,

therefore, to provide a self aligning power driven reamer drive for tting piston pins, which machine includes a rotatable reaming tool and structure operably associated therewith for holding one end of the connecting rod in a position where Athe end having the piston pin bushing therein may be received by the rotatable reaming tool.

A further object of this invention is to provide a reamer drive having structure which permits iree manual movement of the connecting rod through a reciprocable path of travel upon the reaming tool and at the same time allows free movement of said connecting rod laterally in all `directions in transverse relation to the axis of rotation of said Teaming tool, throughout the time the entire machine is placed in operation and while the operator thereof is manipulating the connecting rod. y

A still further object of this invention is to provide a machine for reaming piston pin bushings or' the like having positive self aligning means which includes a longitudinally reciprocable, elongated rod or pin having means on one end thereof for `olampingly holding the conto power driven tools and y necting rod in ninety. degreerelationship thereto.

Another object of this invention is to provide structure having a table `for `supporting the said pin, which table is slidably mounted for movement toward andfrom the reaming tool in transverse relation tol the sliding reciprocable path of movement of the pin, all to'lthe end that the connecting rod and the reaming tool associated operably therewith will be self aligned withoutfadditional effort on the part of the operator other than shifting the connecting vrod longitudinally onthe reaming tool in the conventional manner. i y f l Additional objects of this invention include an unique assembly of reduction gearing, presenting a plurality. of `different driving speeds for the rotatable roaming tool; the way in which a quickly adjusted expander type of holding means formsa `part ofthe above mentioned reciprocable rod for holding the larger babbitted bearing end of the connecting rod in place; and the manner 1in which all of the` associated parts forming the holding means for the connecting rod maintain the samein a. position where the respective axes of the said connecting bearing and the reaming tool are maintained in true and precisely `aligned parallel relationship as the guiding operation takes place.

Referring now more specically to the drawing: l

Fig. 1 is a top plan view of a self aligning hone or` reamer drive for fitting piston pins made in accordance with my present invention.

Fig. 2 is a side elevational View thereof.

Fig. 3 is a cross sectional view taken on line III- III of Fig. 2, looking in the direction of the arrows,` and .i

Fig. 4 is a fragmentary cross sectional View taken on line IV-IV of Fig. 2. l

While the machine about to be described has been `designed `for use` particularly as a means for iinishing the piston pin bushing of connecting rods,\it is contemplatedthat-.the same may well be used for reaming cylindrical bores in any member with perhaps only a slight alteration in some cases. It is well known in` this` art that` connecting rods for internal combustion engines necessarily must be overhauled from time to time, particularly by reshaping and, therefore, enlarging the size of the bore form-` ing the piston pin bushing, whereupon a new piston or wristtpin replaces the original pin.

In the drawing the number IU designates broadly an elongated base forv mounting and supporting all of the. component parts offthe'.

machine, th uppermost face whereof ear one one of its ends has an upturned extension I2, integral therewith and a bracket I4, each having suitable bearings therein for rotatably mounting a shaft I6 at one end whereof is secured a chuck I8. This chuck I8 may be of any of the usual types similar for instance to those used on lathes or the like, for holding a reaming tool 2`Il`.

It is to be understood that when the term reaming tool is used throughout this specification it is not desired to be limited to any precise form of such tool. The same .may well comprise a reamer as at 20 havingk av number of longitudinal cutting blades thereon, or a hone for grinding the walls forming the bore to be reshaped, or any other type of refinishing:

tool.

An arm 22 extends upwardly from the yeX- tension I2 and has swingably secured at the uppermost. end. thereof a shelf .24 thro-ugh the medium of a transverse pin 26 .upon which shelf 24 :electrical: motor 2'8 is mounted. This motor 28zhasvconnection with a suitable source of electrical energy (not shown). and is provided with a rotatable shaftl 3.8 in the. usual manner. A pair of spaced apart :brackets 32 on the base. IIJ andextendingupwardly therefrom .near one end thereof outwardly from extension fI2,.pivotally mount an upwardly extendingyarm 34' by a transverse shaftt36 `and this arm 34' carries a' pair of:v bearings 38 at. the uppermost free end thereof for rotatably supportingra-shaft 48. One end of each'of theshats i6, 38 and 48 .respectively carry a. number: offsheave and .sprocket wheels, as.is:c1ear.in Fig. .1,.fall`to the end .that thezspeed of rotation. of the. shaft lr6. and,y therefore, the reaming tools28, may be selectively varied in accorclance` with the .particular 'desires' of the o-perator-, Itis understood that theV diameters Aof these. Asprockets and sheaves may -well be. varied andthe followingy sizes are,. therefore, for illustrative purposes only.

Shaft. I6 carries. the chuckl and hasvv a A6" sprocket. 42 afXed thereon :and van.8 sprocket 4.4 nearer the, outwardly extending free end thereof. Shaft 30: .ofthe motor .2.8 carries .rst a; 11/2 v pulley 'or sheave 46-,5a 2% sprocket 48"*and-.fl-nallyat the outermost end thereof a 11/2" sprocket 58. Shaft 40 has mounted thereon near the proximal .bearing 38 and 8^ V type pulley 5.2, a 2%?"v sprocket 54' and an lll/2" sprock'ettzifzat the outermost. end thereof.

In thexconnection illustrated sheaves '46; and 52.1' of shafts. 80 and' 48'; respectively are joined by a 'beltl or the 1ike58 andthe sprockets. 42 and 54 of shafts I6 and 48 respectively .have a. chain. 8U passing.A therearound. It is readily seen that motor 28 `driving'iits shaft: 38f'wil1 in turn drive the. idler shaft IIIllv VandA the. shaft I6 carryingchuck :I18Jwi'llcin turn be driven through the `medium of chain 68;.

Other combinations different from that' just described are as` ffollowsz. vThev belt 58 passes around sheaves 46 land 52- in the samey manner a-s'iabovewdescribed and the chain '68 moved to. pass varound.sprockets '44 and' 1256 of vshafts 1.8. andi 48 respectively.` 'Two 'other combinationsv operatev by removing the 'belt-` 58. entirely and: rendering; `theshaft '40' and its sheave and sprockets inoperable. @ne'of these combinations consist fof passing chain '601aroundfsprockets 48 ande-4121 -of -sha'fts381and I'IiA respectively'fand the other bypassing thechain tliaround sprockets ,58: and 44y of shafts SIlfand I6 respectively. In

these latter two instances the shaft I6 is driven directly from shaft 30 of motor 28. It is readily seen that these four combinations drive the reaming tool 28 at a like number of different speeds, assuming that shaft 38 of motor 28 ro-A tates at a given speed.

The table 24 supporting the motor 28 has the end thereof remote from its pivotal connection 2B .held in the upright position illustrated in Fig; 2 by aturnbuckle 62and an elongated screw 64 in threaded engagement with an opening 'formed in the arm 34 has one end thereof bearing. against the.; upright arm 22; tightening or loosening of the chain 68 and/or the belt 58 may be accomplished by adjusting either the turn'louckle` 62er the screw 64 or both as desired.

Thev uppermost face of base I8 at one end thereof opposite to the brackets 32, has a pair of `substantially parallel longitudinally disposed and upwardly extending guides 68 formed therein which fslidably` receive a pair of spaced-'apart groove'sfl formed in-fthe lowermost face of. a reciprocable talcle. lll. These-guidesV and correspondingA grooves irespectively are substantially triangular shaped in the usual manner forl providing a1 way-V for movement. of'. table 10 toward andfromthereaming tool Y2l] and through a. path. of travel perpendicular to. theV axis of? rotation of saidreaming tool 28. This. table'll has formed thereinfintransverse relation and" 'perpendicular to the4 grooves 68 therein a bore '12. fnr .slidably and rotatablyl receiving a. cylindrical rodkor' pin 74. One endf of this pin 7141 proximal to .the reamng tool' 28:2l1as ta cavity extending there into and terminating inwardly from said end thereof. rIlhis cavity T2 constitutesA a slot: for receiving an :ar-m f8 having one end thereof pivotally secured to. :theV rodl 14'. by a transverse pin 'l near` the innermost` end of thevcavity 1.61. Thlisarm 'I8 extends the entire length of cavity I6 and' has :a lset screw 88 threadingly affixed the-rein and- :at its free end. Longer operating screw 82., spacedv inwardly `from .the set screw, extends. entirely through arm` `I8 and is' .in threaded` .engagementI therewith. Although this sliclable rod I4 is. :cylindrical 'throughout the greater portion of its length, the lendthereof having 'cavity 118 therein is reduced' to a square crosssectional contour, as. isv cleanly shown. 'in Fig; V2. The operation. of the; above: described machinerie clearffrom vthe foregoingY and. itis easily. seen Ahcw* connecting .rod 84 is. held place Afor finishing 4the .bushing 88 formed. in one end thereof'. .As is well known, in addi-tion, to :the `loushi'rig y86..iittedfinto a bore formed in one end of connecting.` rodA 84, this; part ofV an. internal combustion engine has on. theopposite end thereof a babbitted bearing 88 including a Abearing cap.A Bil.. When'this connecting rod. 84 'was initially 'formed and manufactured, the axes .off bushing: .86 and the bearing 88 were. parallel and it is'v this factor which. isv utilizedf'ftov attain the objects setv down above. Connecting. rod .84 -isfi'irst 4placed into positionv by slipping; the bearing' A88 over the reduced square .endl of rod T4, whereuponrthe operating screw f82 is moved against .inner wall of cavity 'I6.until'outer' most -Iendl offset/screw 88 bears directly against. the inner face of bearing. 88. It is vobserved at this point ythat setscr'ewA 8Il5'may be'radjusted to theendthatthis entire expanding type. of hold-y ing means including .arm'l8 will accommodate.

differenti sizes o'fbearings `88. When connecting rod '8'4 is so amountedl uponfthe V.rodf'I.4`, thessam'e isy substantially 'perpendicular to rodi 'I4 fand: to

the path of travel of the table 10. This is because of the parallel relation between the longitudinal axis of rod 14 and the axis of rotation of reaming tool 20. The operator then merely grasps connecting rod 84 and moves the same to the position where reaming tool 20 is within the bushing 86 and during operation the same may be reciprocated along the longitudinal axis o reaming tool 20 in the usual manner until bushing 88 is shaped to the desired condition.

It is notable that during this operation connecting rod 84 is free to move transversely with respect to reaming tool 20 due to the free slidable movement of table upon base l0 and is also free to swing vertically because of the rotatable mounting of rod 14 within the bore 12. this floating action in vertical and horizontal planes with relation to the axis of the renishing tool which insures the self-aligning of the bore of the bushing 86 .in parallelism With the bore of the bearing 88. In other Words, as the renishingrtool tends to straighten out a hole which does not parallel the axis of the bearing 88, reciprocation of the table 'i0 and oscillation of the supporting rod 14, permit a shifting in position of the connecting rod 84 to insure that the axis of the hole being reiinished in the bushing 86 will be parallel to the axis of the bearing 88.

It is also notable that movement of table 10 permits different lengths of connecting rods to be nished; that connecting rod 84 is free to be swung in any vertical position desired while the operator moves bushing 86 from rearning tool and that in addition to the entire machine accommodating a conventional reamer 20 having a number of cutting blades thereon, as clearly illustrated in Fig. 1, a hone may be secured in chuck I8 for nal finishing.

This feature of being adaptable for accommodating either a reamer or a hone is extremely advantageous in the machine just described. Most devices of this character on the market today either employ only a hone or a reamer and these tools are either not interchangeable at all or necessitate complicated substitution and change of parts to render the same interchangeable. Furthermore, as far as I am aware, there is no machine of this character in which the end of the connecting rod being finished is supported in such a manner that the Vaxis of its bore is in floating relation to theaxis of the renishing tool without imposing a load on the tool greater than that of the weight of the end of the con- It is' necting rod, and regardless of the length of such connecting rod. This result is secured by the back and forth or rectilinear adjustment of 'the table at 90 to a plane passing through the axis of the refinishing tool and by the additional fact that the crank shaft end of the rod is: mounted .for oscillation around an axis substantially coaxial with its bore.

The drive illustrated and described herein is capable of rotating the shaft I6 at different rates of speed.` When maximum speed is utilized, the hone type tool is employed and when the speed is reduced, a tool of the reamer type is mounted on shaft I6.

Change-over from one speed to another is possible through employment of the parts shown.

Manifestly, many modications may be made to the preferred form herein shown and described without departing from the spirit of the invention or scope of the appended claim.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

A machine for refinishing connecting rod bores comprising a base, a rotatably driven tool journaled on the base, a pair of guides formed on the base and extending at right angles to the plane of the longitudinal axis of the driven tool, a table freely reciprocable on said guides and having a bore paralleling the longitudinal axis of the driven tool, a rod rotatable and longitudinally slidable in said bore and having a cavity at one end and exteriorly formed with a twopoint bearing contact, an arm pivoted at one end within the cavity and formed with a third bearing contact at its other end in opposition to the two-point contact, and a set screw in threaded engagement with the arm and abutting the rod for adjustably spacing the third bearing contact in relation to the two-point bearing contact.

CLAUD C. CRAVEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,603,070 Cox et al. Oct. 12, 1926 1,921,316 Mattern et al Aug. 8, 1933 2,218,380 Evans Oct. 15, 1940 2,414,731 Forbes Jan.. 21, 1947 

